<!DOCTYPE html>
<html lang="zh-CN">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    div {
      width: 100px;
      height: 100px;
      background-color: #17f;
      transition-duration: 3s;
      transition-property: all;

      /*
        速度曲线
         ● ease         慢 → 快 → 慢
         ● ease-in      慢 → 快
         ● ease-out     快 → 慢
         ● ease-in-out  慢 → 快 → 慢
         ● linear       匀速
         ● steps(n)     分成 n 帧
       */
      /* transition-timing-function: linear; */
      transition-timing-function: steps(10);
    }

    div:hover {
      width: 1000px;
    }
  </style>
</head>

<body>
  <div></div>
</body>

</html>